import turtle
colors = ['red', 'orange', 'yellow', 'green', 'cyan', 'blue', 'purple']
colors = colors[4:]+colors[:4]
turtle.left(90)
turtle.pensize(25)
for i in range(len(colors)):
    turtle.penup()
    turtle.goto(160-20*i,0)
    turtle.pendown()
    turtle.pencolor(colors[i])
    turtle.circle(180-20*i,180)
    turtle.left(180)

turtle.done()